In reply to pavlov123:
Went Christmas 2016 / 17, arranging it through www.iranclimbingguide.com. The plan was a big hill (up in the NW, on the site) which didn't happen because conditions were reportedly a bit baltic, & ice-climbing, which somewhat worked & yielded a few good days despite variable early season conditions. On the other hand we got in a few days rock climbing, some of it very good. May is apparently the right time for Bisotun, which looks good, also for the big hill in the NW the name of which I still can't remember. Hamid (who is the eponymous iranclimbingguide) was very solicitous of our welfare & very flexible in adapting the schedule to suit us & the conditions. Were I to go again I would arrange it through him, probably asking for an unaccompanied package (i.e. give us the beta, drop us off, hook us up with whoever is doing the cooking & providing a bed & come back in a week). I think he'd be amenable to that approach. Driving in Tehran is horrible - as bad as anything I've seen - I wouldn't consider it. Pollution in Tehran is also something special (& I live in HK!) but the hills to the north are well worth a visit, & I though the day-trip bolted alpine rock at 3,000 metres was pretty cool. Overall a worthwhile destination - I went with a set of positive preconceptions which were largely confirmed, & I would go back.