We are so used to much cultural heritage around us that we often take it for granted.
However it actually grounds on the efforts that many people have made to sustain it for a long time. 聼起來自然嗎?

For the first sentence, “We are used to so much cultural heritage around us that we often take it for granted.” You could also combine it into two sentences: “…take it for granted, however, it actually…” But the sentence sounds pretty good as it is.