In Catalan and in Spanish we have two verbs: "ser" and "estar" . Both translate into English as "to be". One of the uses of "estar" is to say that something is in a certain state or place. So, for example, in Spanish we'd say: "la belleza a menudo ESTÁ donde menos te lo esperas", which translates into "beauty IS often where you don't expect". My problem here is that I feel something is missing in the English translation: because of using "often", I feel like I should put an adjective or something describing a state after it. So for example I'd say "is often present where....". My question is: is the first translation correct? Or is it necessary to put an extra verb to say that beauty "is located" to a place? In Spanish, "estar" already contains this meaning, hence my doubts.
All of your solutions are correct, and the choice will depend on what kind of tone the speaker wants to set: More formal ... or more casual?
Beauty's in the eye of the beholder is something I might say to my girlfriend when she says I bought an ugly lamp. :-) So that IS is very casual.
One of the lame things about (American) English is that we use is / to-be all the freaking time. We sound pretty generic when we talk, compared to say, Germans. There, yes, they'd more frequently use sich befinden to say where something "is".