LEGO Hidden Side 70437 Mystery Castle [Review]

Welcome back to the Hidden Side! For our second review of the current wave of sets, we are looking at the largest of the five, 70437 Hidden Side: Mystery Castle! This set contains 1035 pieces and retails for US $99.99 | CAN $139.99 | UK £89.99. It is available now in Europe, and will be released later this summer in the US and Canada, likely on Aug. 1.

The box and contents

The box features the Hidden Side “half and half” style artwork that seems to have confused a lot of LEGO fans. As I mentioned in my review of J.B.’s Submarine, LEGO seems to have listened to the fan feedback and made the box art a bit more understandable. An illustration of the full set is visible and we can see one of our main character, Parker, viewing the castle through her ghost-viewing phone. It contains seven numbered bags, one unnumbered bag that holds some of the larger pieces, a 295-page manual and two sticker sheets.

The build

First Floor & Basement: We kick things off on the lower floors of the Mystery Castle where a tentacled horror resides. The porch area is built on top to introduce one of the set’s major play functions. Pulling on a lever mechanism (which you might recognize from past Hidden Side builds) activates a trap door built into the floor just under the front door. The trap door opens and drops our hero right into the tentacled grasp of the monster lurking below. It’s a simple mechanism that controls two tandem movements that are quite effective. The front is finished out with an elaborate front porch that includes two of the Elves fences in light grey. Two additional pieces are added to the main area with hinges to create the bases for the side towers, the bottom levels of which contain jail cells.

Meanwhile on the inside, the door is flanked by two eerie blue flamed candles and a pair of the coolest stained glass windows I’ve ever seen in a LEGO model. While these are stickers, they are worth the application. I’ll definitely be using these in a custom build of my own down the road.

Attic & Right Tower: No spooky abode is complete without an attic and the Mystery Castle follows suit. A small upper area contains a throne for our villain, a small piano and an odd crystal configuration. Also present is the ubiquitous color wheel that allows use of the sets’ AR functions (more on that later). A combination of angled plates and hinges create a nice roof on the front side with a dormer and small tower to top it all off.

The right tower has three floors including the aforementioned basement jail cell. The first floor room has a coat of arms and a box of tools while floor two starts to get spooky. A small podium with a mysterious text stands near the window below a picture of three crystals being activated by a swirly cloud, a reference to the odd crystal configuration in the attic. A lone blur flamed candle sits near the wall, completing the rooms’ decoration. Blue flames and lanterns end up making several appearances in this model.

The Astronomy Tower: What stands this castle apart from some of its’ predecessors is the inclusion of an astronomy tower. While the rest of the castle is built in grey tones, this tower is made using dark tan pieces dotted with dark green windows, giving the feeling that this was something added on to the structure later. Unlike its brother, the Astronomy Tower consists of four floors. The basement dungeon, a first floor with a broom and bucket and the third floor contains a small table with a bottle and cup. Someone’s been busy on floor three! The top floor houses two control panels and a gold telescope. I love the construction of the telescope with its dramatic size change. When looking at the completed model, it’s the first thing that catches your eye. The whole room is enclosed with two large canopy pieces create a pleasing shape that differs from the points and cones used throughout the rest of the model.

The Grounds: The final two pieces of the set make up the grounds of the castle which, when attached to the towers, create what seems like a sea cave. The interior includes plenty of disembodied eyes and tentacles making for a very Lovecraftian feeling. I could easily write an entire article about the overwhelming similarities between Hidden Side’s lore and the stories of H.P. Lovecraft, but perhaps that’s best left for another day. The right side includes an extra tower and a staircase to the Astronomy Tower as a feature while the other side features what seems to be a front gate. This is where the architecture of the building starts to get confusing. What I’ve been referring to as the “basement/sea cave” is accessed by what appears to be a “front gate”.

Meanwhile, the “first floor” has what is clearly a front door but oddly there is no way to actually access that front area. No stairs in the front or back… perhaps one is meant to crawl up the slimy hole, through the trap door and onto the porch? Apparently this is the the real mystery in this Mystery Castle. Once the side pieces are attached to the towers, the whole thing can open, using hinges and a clip and bar in the front to hold the whole thing closed with a satisfying click.

The finished model

The finished model has a nice silhouette with the curved astronomy tower topper breaking up the rocky, pointy-ness of the rest of the building. I am reminded of the Monster Fighters Vampyre Castle set, which sported similar opening and closing side sections that created a sort of courtyard when closed. However, the Vampyre Castle was quite compact when closed and the Mystery Castle has a much larger footprint due to the amount of open space in the “courtyard”.

The minifigures

The set comes with six minifigures divided evenly between heroes and villains. On the hero side we have our main recurring characters, Jack Davids and Parker L. Jackson, plus Parker’s great-great-great-great-grandfather Vaughn Geist Jackson who made his minifigure debut in J.B.’s Submarine. Jack appears this time without his trademark hoodie and instead opts for a backwards baseball cap while Parker returns to her classic jean jacket with plenty of flair. Vaughn is wearing the same western style outfit with bandoleer and face bandanna that he wears in J.B.’s Submarine and several other sets in this wave. Both Jack and Parker have alternate faces while Vaughn does not, although his transparent purple head is pretty cool.

On the other side (one might say Hidden Side!) we have new villain Nehmaar Reem, accompanied by his two matching ghost knight minions. Neem has a nice black and silver outfit, black bat-wing shoulder pauldrons and a fantastic new ghostly lower half. Unlike past ghost leg pieces, this one doesn’t replace the legs, rather the legs actually fit into it. It’s quite large and has wonderful black and trans-blue smoky tendrils. The ghost knights have transparent black heads with a nice eye print and Neem’s head is light aqua with large, reflective silver eyes.

Conclusion and recommendation

The Mystery Castle will be a nice addition for anyone looking to add a reasonably priced spooky castle to their collection. It doesn’t have the color splash of the Scooby Doo Mystery Mansion, but the inclusion of lots of light blue colors in the transparent pieces and stickers keeps it from becoming boring. The astronomy tower in dark tan with its curved roof and large telescope makes for a nice accent to help this castle stand out from its predecessors.

There are some wonderful little details spread throughout that mostly come from an excellent sticker set, like the stained glass windows and the creepy family portraits. I really love the approach to the tentacled, many eyed Lovecraftian horror that resides in the lower level. However, I would have liked to have seen a little more detail in the lower levels of the towers. The jail cells are basically empty and the first floor rooms’ decoration consists of a box of tools in one and a broom and bucket in the other. Given some of the detail in other parts of the set, these rooms seem like a bit of an afterthought. It feels like some more scary elements could have been added rather than mundane cleaning supplies.

For parts collectors, it has a nice selection of pieces for castle builders and devotees of scary things but if you’re buying it for the parts, it will likely be cheaper for you to source the pieces individually as the set tends to be heavy on gray common parts. If you are a fan of stickers, you’ll love the sticker sheet. This set will appeal to people who missed out on the previous haunted castles and can’t shell out top dollar for the new Haunted House. This is a much more affordable alternative if your LEGO town simply must have a haunted castle at the end of the block like all good neighborhoods should.

70437 Mystery Castle is available in Europe now for UK £89.99 and will be available later this summer in the USA, US $99.99 and Canada, CAN $139.99 It may also be available from third-party sellers on Amazon and eBay.

The LEGO Group sent The Brothers Brick an early copy of this set for review. Providing TBB with products for review guarantees neither coverage nor positive reviews.