An user Spanish
says…

Es
Auxiliary
  posible
Adjective
  que
Subordinating conjunction
  fuese
Auxiliary
  una
Determiner
  atalaya
Noun
  defensiva
Adjective
  en
Adposition
  la
Determiner
  antigua
Adjective
  muralla
Noun
.

It is possible that it was a defensive watchtower on the ancient wall.
Words and sentences
New
es

New
fuese

  1. first/third-person singular imperfect subjunctive of ir
  2. first/third-person singular imperfect subjunctive of ser

New
atalaya

New
defensiva

New
en

  1. in, at, on
  2. in (a time)
  3. in (a language)
  4. used after some verbs and translated by various prepositions in English
  5. in (in various expressions)

New
la

New
antigua

New
muralla

large wall built to protect cities or territories

Comments