From an apartment inside a windmill to a centuries-old palazzo with cave pool, these Airbnb rentals offer more than a bed to sleep. Best of all: you can book them for under $200 person a night. Underground Hygge

This Washington state "hobbit hole" is built into the earth with a round doorway above ground, resembling a dwelling you'd find in author J.R.R. Tolkien's Middle Earth. The whimsical, one-bedroom abode with rounded windows and doorways and hanging lanterns has a fireplace, woodwork bench complete with tools if guests want to whittle away, wooden shower and sink and a designated parking area that's a five minute walk away. It's immersed in nature, facing the sunset over the Columbia River Gorge mountains. Rates start at $200 a night and accommodates two guests ($100 per person per night). The Seashell House

This "world famous" house is one of the most popular Airbnb rentals. Located in Isla Mujeres, a quaint island about a 45-minute ferry from Cancun, the giant, sea-shell shaped property with private pool is divided into two separate conches, with one bedroom and bath per conch, and it's a popular island attraction for those strolling along the beach. The house is shell themed, with shell-shaped headboards sculpted right out of the walls, shell-trimmed mirrors and shell showerheads. It rents at $308 per night, up to four guests at $77 per person per night. Windmill apartment

Holland is famous for windmills, and this apartment is literally inside one. Built in 1874, the windmill apartment near Amsterdam (a 15-minute drive) has three bedrooms with double beds, one bathroom, kitchen, dining room and views of the farmland. The windmill is located next to a pond, and the owners live two miles away. Rates start at $423 per night. It accommodates up to six guests, which comes down to $70.50 per person per night. The Houdini Estate

According to the listing, this five-acre property is "reputed to be the former home of legendary magician Harry Houdini." The four-bedroom estate has a heated outdoor pool and Jacuzzi, three fireplaces, terraced gardens, a rock waterfall, natural-spring pond and "romantic gazebos with stunning canyon vistas." What makes the secluded property intriguing is that it still has caves, hidden tunnels and a deep-water tank where "Houdini reportedly practiced his underwater escapes." The house was built in the Edwardian tradition in the early 1900s. It's popular for weddings and events. Rates start at $1,500 a night. It accommodates 12 guests, bringing the rate down to $125 per person per night. Domus Civita

With this rental, you get your very own hidden cave pool. Domus Civita in Lazio, Italy, is a restored, 14th-century palazzo that sits atop Civita di Bagnoregio, a historic settlement. According to the listing, it's "connected to underground caves, etruscan thombs and a Roman water cistern." The three-bedroom property, each with their own private bath, also has a wine cellar, meditation cave room, gazebo with outdoor kitchen and a private chef serving up a home-cooked meal on the evening of your arrival. The cave pool (with separate Jacuzzi) is heated. The pool was voted one of the top five pools in the world by GQ. Rates are $834 a night. The villa can accommodate up to eight guests, which comes down to $104.25 per person per night. Point Arena Lighthouse

This lighthouse in Mendocino County, California, comes with a keeper's apartment. Overnight guests have full reign of the 23-acre grounds, including the lighthouse, after 3:30 p.m. PST (the lighthouse is still in operation from the hours of 10 a.m. to 3:30 p.m.). Guests staying here have full access to the lighthouse tower, trails, museum and gift shop once the keeper leaves for the day, and they can still stick around while in operation. They also receive a complimentary bottle of wine and Mendocino Chocolate Company chocolates. The keeper's apartment has one bedroom, one bathroom and a full kitchen, with gas fireplace, wifi and views of the North Coast. Rates start at $222 a night, which comes to $111 per person. A private Connecticut island