We used to go to JAGS Sports Centre until we realised that we did not make the most of our gym membership. Its on the P4 bus route, next to North Dulwich station. I think its cheaper than Dulwich College. There was a problem with the drains ie smells but I think its better now. I believe ST Dunstans in Catford also operate the same arrangement. We go to Beckenham Spa these days as its a fab clean pool.