14 of the most challenging Lego sets to build

Lego Titanic

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Since they were invented, Legos have been used to bring countless scenes to life in homes around the globe. From licensed pop culture-inspired sets like “Star Wars” and Harry Potter to buildings dreamed up by amateur architects, there are an endless number of things to assemble.

While building Legos may seem easy enough, especially with the instructions provided in each box, the labor it takes to build some of the most difficult sets can take hours — even days. For those who love the process of assembling a Lego creation, the more difficult and time-consuming, the better.

If you’re a Lego enthusiast and are looking for the most challenging Lego sets to build, we’ve got a few that will fit the bill. From unique types of sets to how many pieces it has and its suggested level of difficulty, here are the most challenging Lego sets from 3662 to 10,001 pieces.

1. Lego Ideas Grand Piano (3,662 pieces)

lego grand piano

$399.99 at lego.com

Lego has really come up with some amazing sets over the years and this 2021 winner at the Toy of the Year Awards has to be one of the most intricate. This Lego Ideas Grand Piano set is so advanced, it’s only recommended for adults, with the minimum age listed as 18 years old. Once you’re done putting its 3,662 pieces together, you’re left with a 12-inch wide grand piano with 25 playable keys.

2. Batcave Shadow Box (3,981 pieces)

lego batcave

$399 at Lego.com

The 3,981-piece set includes seven Lego minifigures including two versions of Batman, Bruce Wayne, his butler Alfred Pennyworth, Catwoman, Penguin and Max Shreck. The Batcave tableau measures more than 20 inches wide and 11 inches tall. It has multiple moving parts including a turning chair, a changeable computer screen, a tool store that opens and closes and, finally, an illuminated Batsuit vault.

3. Lego Ideas Home Alone House (3,955 pieces)

lego home alone house

$299.99 at Lego.com

This set has everything you need to re-create nearly all of your favorite moments from the film. With 3,955 pieces, this massive Lego set could be a long-term project that the family works on each day leading up to Christmas. Once complete, the front of the house opens to reveal various rooms of the home that became a series of traps for the movie’s villains.

4. Lego Icons Natural History Museum (4,014 pieces)

lego natural history museum

$299.99 at Lego.com

This cute museum Lego set offers two stories full of treasures, including a towering brachiosaurus skeleton, a telescope, astronomy exhibits and ancient artifacts. The set features a roof that has dual skylights and seven minifigures to bring your scene to life. There’s even a dog figure and an exhibit that refers to past Lego sets! When finished, the set is 12 inches tall and 15 inches wide.

5. Lego Loop Coaster (4,124 pieces)

lego roller coaster

$399.99 at Lego

The Lego Loop Coaster features a vertical elevator tower, plenty of twists and turns, and a height of 36 inches, making it the tallest Lego ride ever. You get motorized components to bring cars to the top of the track and 11 minifigures to ride your thrilling roller coaster in this Fairground Collection gem.

6. Lego Disney Castle (4,837 pieces)

lego disney castle

$399.99 at Lego.com

This iconic Disney castle, which was released in celebration of the Disney company’s 100th anniversary, is modeled after Cinderella’s castle. Inside, you’ll find references to 14 different movie classics, from “The Princess and the Frog” to “Sleeping Beauty.” With a height of 32 inches, this one will take a little time to build, but you’ll love all the Easter eggs and Disney magic you experience along the way.

7. Marvel Avengers Tower (5,201 pieces)

lego avengers tower

$499.99 at Lego.com

This detailed Lego set inspired by the Marvel superhero films will be almost 3 feet tall when you complete the build. It features 31 minifigures, from Iron Man to Nick Fury, so you can recreate some of the Avengers’ most exciting moments. Even Kevin Feige, president of Marvel Studios, is represented here. Take off the side and roof of the building to view the interior, which includes accessories like Chitauri chariots and the Tesseract.

8. Lego ‘Star Wars’ Venator Republic-Class Attack Cruiser (5,374 pieces)

lego venator

$649.99 at Lego.com

This Ultimate Collector Series version of a “Star Wars” Republic gunship is to scale, and it’s one of the largest Legos you can buy new on the market these days. It measures 43 inches long and, in celebration of “The Clone Wars”‘ 20th anniversary, features Captain Rex and Admiral Yularen minifigures. It will take you some time to build, but the level of detail will astonish you.

9. Harry Potter Hogwarts Castle (6,020 pieces)

lego hogwarts

$462.00 at Amazon

Lego has rolled out some impressive Harry Potter-themed kits in recent years but this Hogwarts Castle one is the most epic. It boasts more than 6,000 pieces, which come together to create a 27-inch wide replica of the world’s most famous school for witchcraft and wizardry. Minifigures of the four founders of the Hogwarts houses are included, along with a host of accessories.

MORE: 26 gift ideas for kids (and adults) who love Harry Potter

10. Lego Icons ‘Lord of the Rings’ Rivendell (6,167 pieces)

LOTR lego

$499.99 at Lego.com

One of the most impressive setpieces in the “Lord of the Rings” movies was of Rivendell, an Elven valley settlement that offers beauty and sanctuary for Bilbo, Frodo, and their companions. This Lego version offers 15 minifigures and references to epic movie moments, from an elven forge and paintings to the table around which the Council of Elrond was formed and the Fellowship was created.

11. ‘Star Wars’ AT-AT (6,785 pieces)

lego at-at

$849.99 at Lego.com

These iconic all-terrain armored transports, introduced during the battle on Hoth in “Star Wars: The Empire Strikes Back,” remain a favorite of franchise fans — and this one has rotating cannons, movable and posable legs, and plenty of details that everyone will love. You also get minifigures of General Veers and Luke Skywalker (and yes, of course he can attach to the AT-AT with a cable).

12. ‘Star Wars’ Ultimate Millennium Falcon (7,541 pieces)

Millennium Falcon

$817.90 at Amazon

Any “Star Wars” fan and Lego expert would love to have this epic set in their collection. The Ultimate Millennium Falcon comes with more than 7,500 pieces and is recommended for builders ages 16 and up. It has a lowering boarding ramp and a concealed blaster cannon. It also comes with seven minifigures that span the history of that beloved ship.

13. Titanic (9,090 pieces)

lego titanic

$679.99 at Lego.com

It’s not just the massive scale of the legendary ship that makes the set so huge — this tinier Titanic is unusually detailed. The completed ship can pop open into three sections, allowing admirers to peek inside. The model features the Titanic’s dining room, the famous first-class staircase and even the ship’s engine room, complete with moving pistons on the motors. The propellers really turn and the anchor really drops. They even included lifeboats!

14. Lego Icons Eiffel Tower (10,001 pieces)

lego eiffel tower

$629.99 at Lego.com

No one can argue that the Eiffel Tower of Paris, France belongs in the Lego Icons series — and this version is epic, with more than 10,000 pieces for master builders. From a French flag and observation decks to benches on the Esplanade, this set pays tribute to the tower’s original architecture with a set you have to put together in four parts. At the end, you’ll have a Lego piece that stands almost 5 feet tall.

MORE: The new Lego Insect Collection has arrived, complete with a soundtrack

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