CorbelArchThecorbelarchdiffersfromatruearchinthatthe
corbelusescantileveredblockstobuildthearchandtherefordoesnothaveakeystone.
Itisaweakerdesignandgenerallylimitsthebuildertoahigher,narrowerarch.Thebenefitisthatifyouonlyhadasmallcreektocrossandflatrocksasamaterialitwouldbeaneasycrossingtomake.