I have been going through Alex Harrold's podcast in the Tim Ferris show, and there he says that there are only two climbers in the world who have successfully climbed a 15C difficulty wall.
Were there really only two climbers? Which climbers have achieved this?
On a search, I found that one was Adam Ondra. Who else has done so?
Both Adam Ondra and Chris Sharma climbed La Dura Dura, 9b+/5.15c.
In addition to Sharma and Ondra pre-2018, there have been a few more 15c ascents since then:
Alex Megos did the first ascent of Perfecto Mundo 5.15c in May 2018, and this was repeated by Stefano Ghisolfi and Jakob Schubert
Stefano Ghisolfi repeated Ondra's Change in September 2020
Will Bosi did the first ascent of King Capella 5.15c in March 2021
Also worth mentioning that there are 2 established 5.15d (!) routes as of May 2021:
Both unrepeated, of course.
Source: Wikipedia
toasti is correct, here you can find an (excellent) list of the most difficult sport climbing, bouldering and free solo problems (9b+/15C but also 15B/9b etc.). The spreadsheet lists sources for each first ascent (FA). It contains not only FAs but also repeats (and differentiate between proposed and repeaters' grades). Grades are French / Font:
https://docs.google.com/spreadsheets/d/1RndNw9F74rvgvqDA1i512MwxHf7PtacojVD4s7DHVz8/edit?hl=en#gid=0
The source confirms toasti's answer. La Dura Dura in Oliana, Spain, is yet the only 9b+ which has been confirmed by the repeater. There are however two other 9b+ (Change at Flatanger, Norway, and Vasil Vasil at Sloup, Czech Republic) and one 9c (Silence at Flatanger) firstly ascended by Adam Ondra which have not been repeated (and for that reason have not been confirmed).
Update: Since I received a down vote, I want to clarify that I am not the creator of the spreadsheet nor do I know him. Yet, I think this source is an interesting link for everyone who is interested in the question asked (or similar questions).
