fluctuated throughout the 19th century; in 1815 its height was estimated to have been as much as 60 metres (200 ft). It continued to erupt until the turn of the 20th century, when another earthquake blocked the conduit again. In 1963, upon the advice of the Geysir Committee, locals cleaned out the blocked conduit through the bottom of the basin, and the geyser has been regularly erupting ever since. Strokkur and its surrounding areas regularly attract tourists hoping to see the geyser erupt, as it is one of a very few natural geysers to erupt frequently and reliably.