In Welsh NP/DPs, the head noun precedes PP and AP dependents:
In what I will call the possessive construction, the head noun also precedes the NP/DP possessor: only adjectival modifers of the head noun may intervene between possessum and possessor. The possessor precedes all PP dependents of the head noun. The same descriptive content (as the possessor) can be expressed by a PP (generally headed by the preposition gan:by), but the possessive construction itself is completely general and not restricted to any subclasses of N as possessor or possessum.2
The use of a definite determiner (there is no indefinite article) is absolutely excluded in the possessive construction: the definiteness of the most deeply embedded possessor determines that of the NP construction as a whole. When there is no possessor, the head noun may be preceded by the definite article (a phonological clitic) and other determiners (see (1), (2)).