This 100m structure wasn't the winner of the Çanakkale Antenna contest, a communications tower that will be built in Çanakkale, Turkey. This makes me sad because it looks like a lot more fun to me, even if those glass pods wouldn't move through that loop at roller coaster speeds.
I guess the pods would take visitors to the top and then down always maintaining the same orientation too. According to its creators, the architecture studio AL_A:
A pioneering move to split the antenna in two became the creative technical solution to unlock the potential of giving visitors the unique opportunity to ascend to the very top of what would otherwise be an ordinary telecommunications tower and allowing them a three dimensional spatial experience within the imaginary threshold of East and West.
Visitors ascend almost 100m to the pinnacle of the Tower in gondolas fixed to a track within the structure, with interest at every height as visitors travel up to the highest point of the Tower before descending the opposite side.
ArchDaily has a selection of the other proposals. These two are my other favourites:
A spiral by Erdem Tüzün, Fernando Romero, and Yelta Köm.
The project by Özer/Ürger.