Back to opportunities in real estate: if you were tempted by the Minneapolis skyway but you’re saving your money for something a bit warmer throughout the year, consider snapping up the “Submarine Pits on Boca Chica Key.”

As Sotheby’s describes the carved landscape of submarine docking pens, the pits can be found amidst “approximately 122 acres of vacant land just north of Key West.”

They’re basically just deep slots blasted through the coral and limestone, barely visible beneath the water line in the form of somewhat ominous black strips where the ground drops away.

The site is zoned as a “Commercial Fishing Special District,” perhaps implying some future reuse of the submarine pens as exotic fish farms.

But imagine all the weird opportunities here for submerged foundations, underwater hotel rooms, or other half-aquatic facilities—even something like the Danish National Maritime Museum by BIG—looped in and around these linear, Nazca-like features.

From Sotheby’s:

This parcel was used by the Navy Air Station to house its submarine war ships during the Cuban Missile Crisis and has a very colorful and distinct history. Perfect for marine use and development in a great location. Property includes seven finger cut coral canals that are 90 feet wide and over 25 feet deep, plus a deep water basin with dredged entry channel that provides passage to Boca Chica Channel (Oceanside) and Key West Harbor (Bayside).

The asking price?

A mere $21.2 million—but then these drowned geoglyphs in the semitropical sun can be all yours.