Ynys Hir Nature Reservetop
An RSPB reserve, Ynys Hir is made up of salt marshes, wet grassland and woodland - part of which is said to date back to the 17th century.
The name means "long island" in Welsh referring to a wooded ridge which was once surrounded by marshland.
The area was a private estate until it was bought by the RSPB and became a reserve in 1970.
There are seven hides dotted around the thousand acre sanctuary, offering spectacular vantage points across the estuary.
There are also several marked nature trails - the shortest route is 0.5m and the longest, three miles.
Ynys Hir is probably best known for its Greenland white-fronted geese. Every year, around 150 of them fly in to spend the winter in this part of the world and it's their only regular wintering site in the whole of England and Wales.
Winter is also a good time to see other wildfowl and the estuary attracts thousands of ducks such as wigeon, teal and Canada geese.
In the spring and summer, the oakwoods attract two species of woodpecker in addition to the usual woodland species.
The RSPB has put up special bird boxes around the reserve which are used every year by more than a hundred pied flycatchers.
The Dyfi estuary is also one of the few strongholds for breeding lapwing and redshank in Wales. Feeding cormorants, goldeneyes and red-breasted mergansers can be seen from the Domen Las Hide.
Even if you're not a keen bird-watcher, Ynys Hir is a lovely place to go for a walk - especially in the spring when the woodlands are carpeted with bluebells.