Giving you all information about forecasting weather all over the country.
Iran currency Converter
Converting all currencies to Iranian Rial. (Note that as mentioned before, there is a difference between Rial and Toman. Iranian mostly omit one zero of the price and call it Toman- 1000 rial equals to 100 toman).
(Never underestimate the traditional restaurants with their delicious local food)
All about Tehran
Wikitravel is really comprehensive when it comes to Tehran.
You can simply scroll on the map and find the place you are looking for. This website has some other useful tools including the ability of routing by car bus and etc., the location of the attractions, events taking place in the city and etc.