The Town of Oban
There are several boat trips available to see wildlife which includes puffins and other seabirds, seals, minke whales, dolphins and basking sharks. (whale and shark sightings are seasonal) Fishing is also a possibility.
If you have a few days in Oban, you might want to take some short trips to some of the surrounding areas. The Atlantic Bridge at nearby Seil Island and then onwards to the Island of Easdale is a great day out. Another small trip to the Scottish Sea Life Sanctuary at Barcaldine or maybe a visit to the "Hollow Mountain" at the Cruachan Dam Visitor Centre is worth a visit and on the way back you could visit the Inverawe Smoke House or perhaps the Iron Furnace at Taynuilt. There are so many places to visit and things to see that it is highly unlikely you will be bored!
If you enjoy the outdoors, there are cycle tracks, walks, beaches, a dive centre Kayak hire coupled with tuition, dingy sailing and much more.