The Inverted Tower in Sintra Portugal.

Quinta da Regaleira is an estate located near the historic center of Sintra Portugal.It is classified as a World Heritage Site by UNESCO within the "Cultural Landscape of Sintra". Along with other palaces in this area ,it is one of the principal tourist attractions of Sintra. It consists of a romantic palace and chapel and a luxurious park featuring lakes, grottoes, wells, benches, fountains, and a vast array of exquisite constructions. The palace is also known as "Palace of Monteiro the Millionaire", from the nickname of its first owner, António Augusto Carvalho Monteiro. [wiki]

An underground tunnel with a spiral staircase, supported by carved columns, down to the bottom of the well through nine landings. The nine hole round landings, separated by fifteen steps, evoke references to Dante's Divine Comedy, and may represent the nine circles of hell, paradise, or purgatory.

The well is connected to laberíticas caves that lead to a spooky garden surrounded by a lake. [Image source]
Also See Colourful Flying Umbrellas, Portugal.