Foss á Síðu in southern Iceland.
Foss a Sidu is a waterfall to the east of Kirkjubaejarklaustur in southern Iceland. It is located near the Ring Road, and tumbles down cliffs near an isolated farm. This waterfall does have one unique aspect, however, in that it is known to regularly flow uphill during strong winds from the sea. The waterfall is only a single, narrow stream and quite light compared to some of the raging torrents elsewhere in Iceland. It is quite scenic, however.