Kolona is a double beach. An isthmus of sand links an small islet to the main island of Kythnos, making a beach on either side of the sand bar. Kolona is a short distance from Kythnos’s main port of Merichas.
It’s a popular anchorage. There’s a restaurant on the beach which is open during the day. The beach gets extremely busy in high season and other than a couple of trees there’s little shade. So you might want to take your own parasol.
Those who are fit can make the walk in to Merichas. It’s about 3 miles. However, the first part of this is along the narrow road which can be a bit intimidating. It’s better to arrive sufficiently provisioned to sustain yourselves once the restaurant closes.