Figueira de Castelo Rodrigo
The municipality borders the frontier with Spain , formed by the Águeda River , a tributary of the Douro , which it joins at Barca D'Alva , approximately 18 km north of Figueira de Castelo Rodrigo town . 
<triplet> Águeda River <subj> Douro <obj> mouth of the watercourse <triplet> Douro <subj> Águeda River <obj> tributary