The Zlatni Piasatsi Nature Park
Behind the resort of Golden Sands is the protected area of theZlatni Piasatsi Nature Park. This is a woodland park about 9 km long and just over 1 km wide which covers the hillside overlooking the Black Sea. 90% of the park is mixed deciduous forest, predominantly oak, and is host to many rare and endangered plants. As well as the flora there are over 70 bird and 25 mammal species.
The park is criss-crossed by several well-maintained hiking trails which have colour-coded markers painted on the trees - in fact they are better signposted than than most Bulgarian streets! From Golden Sands the main entrance point is across the road from the bus stop. From here there are two trails, blue and yellow, which lead up to the Aladzha Rock Monastery. The yellow trail rises quite gently, taking a meandering path over its 3 km length. The blue trail is more direct (about 2 km) and also much steeper as it rises the 250 metres of elevation to the Monastery.
Unless you're feeling particularly energetic when visiting the Monastery it's best to take the yellow path up and then come down using the blue. Both trails cross the red trail which runs the whole length of the park.
Website below has loads of useful information (in Bulgarian and English) and a printable map.