Mt Esja watches over Reykjavik like a guardian angel. The mountain is very popular for hiking. A relatively easy hike, the 914 metre high mountain offers stunning views of the entire capital area. There are several routes up and around the mountain, depending on skill.
Esja is located in Kjalarnes, past Mosfellsbaer Town just east of Reykjavik. It is accessible by public transport: Take bus number 15 from Hlemmur bus station, get off at Haholt in Mosfellsbaer, then take bus number 27 to the foot of Esja at Esjumelar.
Don't forget to sign the guestbook at the peak, however. The elves get very upset if you do.