Мария, это поэма Пушкина "Медный всадник". Там рассказывается о наводнении в Петербурге, но в самом начале поэмы идёт речь о Петре, как он основал и заложил город.

Отсель грозить мы будем шведу = From here (from this location) we will present threat to the Swedes, we will be a threat to them... Такой смысл.

Природой здесь нам суждено
В Европу прорубить окно = It is ordained by nature that we shall cut through the window to Europe from here. (famous metaphor is that Peter I cut through the window to Europe, and Russia started to deal with Europe on a large scale since his reign).

Probably, the word order is a bit confusing here, which changes often in poetry. In standard speech the word order would be more usual.

"Медный всадник" is a famous monument to Peter I.