Þingvallakirkja (Church of Þingvellir) is a church within the old assembly site. The current building was built in 1859, replacing the former one and thus becoming the most recent one in a line of several churches. It's belltower was added in 1907, the date written on it's weather vane. According to the saga's, a church has been standing at Þingvellir since the year 1017, no more than 17 years after Iceland's convertion to christianity by law.
Þingvallakirkja is open from June 1st - August 31st, as long as there is a park ranger present. Commonly that's 9:00 - 10:00 in the mornings, and 13:30 - 17:00 in the afternoons. Þingvallakirkja is closed during winter except when services take place at irregular times.
The priest at Þingvellir operates from Skálholt which used to be the cathedral of Iceland for centuries. For booking the church or other church related questions please contact thingvellir@thingvellir.is. Price for renting the church is 20.000 ISK.