"Beaches are very nice here."
Translation:Les plages sont très belles ici.
I know that this is a common translation from English to French. I could be wrong but, would the reverse translation of "Les plages sont très belles ici" really end up with the word "nice" in English? I know that "belle" can mean pleasant and nice. But wouldn't "Une tres belle plage" be referring to the physical beauty of the place? Whereas "a nice beach" in English is more general. I think a better translation of the English word "nice" in this sentence would be "plaisantes". But "Les plages sont très plaisantes ici" is not accepted.
Adverbs of place, especially simple directional pointers like ici, là-bas,à l’intérieur, etc., move around a bit. They usually follow a direct object, but even in a sentence without a direct object they are normally at the end of the main clause (or sometimes at the beginning of the sentence).
The reason I asked "which adverb" in my original response is because both "très" and "ici" sound so natural in their placement in this sentence to me that I was confused by your question. Sorry.