Boulder wall

A boulder wall, also spelled boulder-walls or bowlder-wall, is a kind of wall built of round flints and pebbles, laid in a strong mortar. It is used where the sea has a beach cast up, or where there are plenty of flints.

 This article incorporates text from a publication now in the public domain: Chambers, Ephraim, ed. (1728). "^{article name needed}". Cyclopædia, or an Universal Dictionary of Arts and Sciences (first ed.). James and John Knapton, et al. 

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