touristic bulak mencilis cave with walking path. safranbolu, karabuk

attraction bolu bright bulak calcite cave caves colorful column dark deep detail formation geologic geological inside interior karabuk karabafrac14 karst landmark light lighted limestone magara magarasi maaara maaarasaplusmn mencilis old orange red rock rocky safran safranbolu shine sparkle speleology stalactites stalagmite stalagmites stone tourism tourist tunnel turkey tafrac14 rkiye underground water touristic walking path path