You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Estonia

Context:
In the first centuries AD, political and administrative subdivisions began to emerge in Estonia. Two larger subdivisions appeared: the province (Estonian: kihelkond) and the land (Estonian: maakond). Several elderships or villages made up a province. Nearly all provinces had at least one fortress. The king or other highest administrative official elder directed the defense of the local area. By the thirteenth century Estonia consisted of the following provinces: Revala, Harjumaa, Saaremaa, Hiiumaa, Läänemaa, Alempois, Sakala, Ugandi, Jogentagana, Soopoolitse, Vaiga, Mõhu, Nurmekund, Järvamaa and Virumaa.

Question:
What type of structure did most provinces have?

fortress