John McCarthy focuses on the Caucasus, the mountainous region between the Black and the Caspian Seas. It contains Europe's highest mountain and landscapes ranging from subtropical to Alpine and semi-desert. It is ideal walking country but international tensions, particularly between Georgia and Russia, have meant that it is not as well visited as it deserves to be according to Oliver Bullough and Peter Nasmyth who have both travelled widely in the region. Doug Patterson is a painter and architect who, following in the footsteps of 18th and 19th century artists, has painted monasteries and mosques across North Africa, Greece, India and Bhutan. He talks to John about what, despite the differences in religion, the buildings and locations have in common - including those in Greece and Bhutan which are perched on or cling to cliff faces.