Longest rock climb in the world?

At Calanques:
https://verticalpirate-escalade.com/topos-escalade/france/calanques/castelvieil/les-grandes-traversees-maritimes/

The longest normal traverse is like 800m, but you could do several together for a couple kilometer's worth of climbing

In the Eastern limestone alps there are also some monster routes with reasonably sustained difficulty:

Pinzgawurm, 2000m:

http://www.schmidt-zabierow.at/pages/klettern/pinzgawurm-45sl.php

Endenie, 1500m:

http://www.schmidt-zabierow.at/pages/klettern/endenie-38sl.php

Gletscherbaeurin, 1700m:

http://www.schmidt-zabierow.at/pages/klettern/gletscherbaeurin-33sl.php

Also Monte Agner.

And of course, nobody has mentioned the Puerterey Integrale, though not purely rock, has probably the most rock climbing in a route in the Alps.

9200ft...! Anyone done this thing?

The tread wall!

regaljay -wrote:

And of course, nobody has mentioned the Puerterey Integrale, though not purely rock, has probably the most rock climbing in a route in the Alps.

Peuterey:

https://www.mountainproject.com/route/112041740/peuterey-integrale

Roughly 4,500m long.