Learn Portuguese (Portugal): A escola é à esquerda.

In Portuguese, you are often taught that the verb estar is used for locations. However, in European Portuguese, we frequently use ser (like é here) to state the permanent location of a building or a place. It is also very common to use the verb ficar for this.

Why does the "a" in "à esquerda" have an accent pointing to the left?

That accent (called a grave accent) shows that two words have merged into one. It combines the preposition a (at or to) with the feminine word for "the", which is also a. Together they become à.

Why do we use "à" instead of "na" for "on the left"?

In English, you say "on the left", but Portuguese uses the preposition a (to/at) for these directions. So the phrase is literally "to the left" or "at the left". You will use this same pattern for "on the right" (à direita).

Is "esquerda" always feminine?

Yes, when talking about directions, the concepts of "left" and "right" are treated as feminine nouns: a esquerda and a direita. This is why the preposition a combines with a feminine "the" to make à in this sentence.