Learn Italian: Quanto bene conservano il patrimonio italiano! - How well they preserve the Italian heritage!

While come means 'how' in questions, exclamations work a bit differently. To exclaim 'How well!' or 'How much!', you use Quanto before the adverb. If you wanted to use come, it would attach to the verb instead, like this: Come conservano bene il patrimonio italiano!

Could I use Che instead of Quanto in this exclamation?

Che is often used before nouns or adjectives in exclamations (like Che bello! for 'How beautiful!'). However, when you are modifying an adverb like bene (well) or male (badly), Quanto is the standard and most natural choice: Quanto bene!

Where is the word for 'they' in this sentence?

It is built right into the verb! The -ano ending on conservano tells us the subject is 'they' (loro). In Italian, you almost always drop the subject pronoun unless you need it for strong emphasis or to avoid confusion.

I see conservano is translated as 'preserve'. Does it also mean 'conserve'?

Yes, the verb conservare translates to 'conserve', 'preserve', or even just 'keep' depending on the context. When talking about historical sites or culture (il patrimonio), 'preserve' is the most natural English translation, but the core meaning of protecting something is the same.