Hammargren, born in 1937, is a lifelong memorabilia collector. On the state’s annual Nevada Day, which celebrates the state’s admission to statehood in 1864, he opens his Las Vegas abode to visitors for an open house, drawing thousands of visitors each year. Hammargren spends more than 50 hours each week on his “Hammargren Home of Nevada History,” carefully organizing his ever-growing trove of memorabilia, with occasional help from his wife Sandy. Though he keeps joking that each item will be the last, the collection has never once stopped growing, and likely won’t stop anytime soon.

His wunderkammer includes an underground mine, a mini Taj Mahal, a T-rex replica, and an animatronic tiger, to name just a few things you might find. Most of the collection is tied into two of Hammargren’s central passions: education and science, and many of them have required cranes and some serious manpower to transport into place. There is also plenty of Nevada and Las Vegas pride on display.

Though most of his collection has been built on donations, Hammargren has also spent $10 million out of his own pocket on purchases, construction, and maintenance.

According to atlasobscura.com and en.wikipedia.org