Thessaloniki, definitely worth a visit. Superb promenade, vibrant town centre. Walk the 4K to town along the seafront. Not for swimming but great for sunsets. Hop on thé 3,5 or 6 buses and go to the centre. Great cafes and restaurants. Loads of shops and museums a plenty! The flat we stayed in was spacious and comfortable, in a quieter area of town, which suited us fine.