Cemlyn nature reserve lies on the north of Anglesey, near the village of Cemaes and the Wylfa power station and is owned by the National Trust.
The reserve however has been leased and maintained by the North Wales Wildlife Trust (NWWT) since 1971 who monitor the terns here each year.
A large shingle ridge separates the sea from the salt and fresh water lagoon, which becomes a hive of activity in the summer months when terns arrive to nest here.
Clustered on islands in the lagoons are large and internationally important sea bird colonies, including common and arctic terns. It is also one of the UK's largest nesting populations of sandwich terns.
The beauty of this particular spot is that you can get incredibly close to the birds without disturbing them.
Visitors and birdwatchers alike can sit on the shingle back opposite and watch the birds flying and back and forth over head, as they return from the sea with fresh catches of sand eels and fish.
It's also a good spot to see migrating waders such as the grey and golden plover and purple sandpiper and ducks, including the golden eye and shoveler.
The shingle ridge is also home to many interesting coastal plants such as sea kale, sea campion and yellow horned poppy.
The Anglesey Coastal Path passes through Cemlyn and if you're lucky, you might also spot a seal, porpoise or dolphin out at sea here.
The farmland beyond the coast is great habitat for dragonflies, adders and lizards and the old outbuildings at the back of the reserve provide a perfect location for owls.
Cemlyn is a Special Protection Area, a candidate Special Area of Conservation and a Site of Special Scientific Interest. It is also part of the Anglesey Area of Outstanding Natural Beauty.