A pele tower is a small fortified tower, like a miniature castle.
In warlike times in the English-Scottish border area they provided a refuge so that when cross-border raiding parties came the whole population of a village could take to the tower and wait for the marauders to depart.
Peles are not usually found in larger places which have a castle, but in smaller settlements. They are often associated with a church: for example the pele tower in Embleton is a fine example of a vicar's pele and the one at Hulne Priory is in the grounds of the priory.
Nowadays some are derelict while others have been converted for use in peacetime; the Embleton pele is now part of the vicarage and that on the Inner Farne is a home to bird wardens. The most obvious conversion needs will include access, which was originally difficult, and the provision of more and larger windows.