Grundkallen is a Swedish lighthouse on a shallow of the same name in the southern part of the Gulf of Bothnia, some 20 kilometres (12 miles) northeast of Öregrund.

[2] On 3 March 2004 at around 00:30 (UTC+02) a Finnish pusher-barge combination Herakles-Bulk sank near the Grundkallen lighthouse.

The combination had left Oxelösund two days earlier and was heading north with the barge fully laden with coal.

On 2 March she ran into a storm and the captain, not certain if the vessel could be safely turned around in such conditions to seek shelter closer to the coast, decided to evacuate half of the crew by helicopter.

The remaining crew was soon evacuated and shortly afterwards Herakles-Bulk collided with the lighthouse, causing superficial damage, and foundered in the nearby shallows.