Cehennemağzı Caves
... that one of the Cehennemağzı Caves in northwestern Turkey features a very old Christian church, which was used as a secret place of worship in the first years of Christianity?
... that one of the <b id="mwB50"><a href="./Cehennemağzı_Caves" id="mwB54" rel="mw:WikiLink" title="Cehennemağzı Caves">Cehennemağzı Caves</a></b> in northwestern Turkey features a very old Christian church, which was used as a secret place of worship in the <a href="./History_of_Christianity#Early_Christianity_(c._31/33–324)" id="mwB58" rel="mw:WikiLink" title="History of Christianity">first years of Christianity</a>?