Learn Dutch: Buiten hebben we naar de horizon staan kijken. - Outside we stood looking at the horizon.

Buiten means you are already outside. If you were moving from inside to outside, you would use the directional form naar buiten (to the outside). Because the action of standing and looking happened entirely in that location, the absolute spatial adverb buiten is used.

Why does the sentence end with the infinitives staan kijken instead of a past participle like gekeken?

This uses the double infinitive rule. In the present tense, you use staan te kijken to mean you are standing and looking. But in the perfect tense (have stood looking), verbs like staan, zitten, and liggen drop the te and stay as infinitives. Because of this, you don't use a past participle like gestaan or gekeken, but end up with two infinitives: hebben ... staan kijken.

Why is the word order hebben we instead of we hebben?

Because the sentence starts with the adverb Buiten. In Dutch, when anything other than the subject is put in the very first position of a sentence, the verb and the subject swap places. This is called inversion.

Does kijken always take the preposition naar?