There is lots to see on holiday in Bulgaria, but stick to the centre of capital Sofia to avoid the Soviet concrete towers that crowd the suburbs. Visit the cavernous neo-Byzantine Alexander Nevski Memorial Church, Church of St George, which dates back to the 4th century and the spectacular domed Sveta Nedelya Cathedral. Museums include the Archaeological and Ethnographical Museums. The Borisova Gradina Park is nice for a bit of greenery and Mineral Baths are great for relaxing and admiring the ornate architecture. 8km from the centre is Boyana, home to the National Museum of History and the 13th century Boyana Church - it's definitely worth a detour.
On the Black Sea, there are many thermal spas with mineral pools and curative mud treatments. They include Golden Sands, St Konstantin, Elena, Varna and Albena. Visit the Baltata Nature Reserve near Albena and the well preserved Roman baths in Varna. South of Sofia, the Pirin National Park has some excellent walking trails, while in Bulgaria's centre, Rusenski Lom National Park features some lovely churches.
South of Sofia is Mount Vitosha where you can ski in winter or hike in summer. You may even want to venture as far as the former capital Veliko Tarnovo, 150 miles from Sofia, which is a breathtakingly beautiful city where houses perch precariously on the sides of cliffs overlooking the Yantra River Gorge.
From Golden Sands take a walk through 1,320 acre Golden Sands Nature Park full of shady forested trails - you might even make it to the monastery beyond. If you're staying on the north coast, Balchik is worth a day out, the town is quite charming and untouristy, and it has a fine, if small, palace within a 35-hectare collection of gardens and water ways.