The main attraction in Ilulissat is the Ice Fiord. 35 kilometers from the city is a glacier constantly delivering icebergs into the Fiord. The speed of the glacier has increased from 22 meters/day in 2002 to now (2007) 35 meters/day as a result of global warming. The fiord is 500 meters deep, so the iceberg floats to Ilulissat where they hit a barrier, as the fiord is only 250 meters deep at the mouth to the Disko Bay. So here the icebergs get stuck until enough ice has melted so the iceberg can pass the barrier. As 8/9 of an iceberg is below below sea level you'll see a lot of icebergs 20 to 30 meters high.
The Fiord can only be reached by foot or boat (or by helicopter). It's a fairly easy walk from the city and after 1-2 kilometers' you'll see the icebergs - an impressive sight.
You may take a 3-4 hours boat trip from the harbour - also a recommended tour