Herdisavik is a stunning site. It is a ridge which runs for at least 15km.
The launch feels scary but it is actually an easy site to fly. The ridge lift is smooth and consistent.
Here are some videos from the site:
http://www.vimeo.com/13121416
http://vimeo.com/5188359
Access
This map view shows the approaches from the east and west:
http://ja.is/kort/#x=365265&y=389242&z=4
From the west, go past Krysuvik.
From Reykjavik it is faster to go east, towards Selfoss, then turn onto road 39, then 427.
Rules
The site is underneath FAXI TMA. Keflavik TMA (from SFC) is approx. 10km to the NW. See: http://www.caa.is/media/PDF/AD_2_BIRK.pdf and http://www.caa.is/media/PDF/ENR.pdf for details.
In Northerly winds, commercial flights will approach Keflavik along the coast. Height restriction of 3000 feet/914m AMSL.