no puedo esperar a ver

Question

I have 2 questions about "no puedo esperar a ver":

1. First I was surprised by the 'a' after 'esperar'. When do you use this construct rather than esperar on it's own?

2. In the grammar link for that sentence it says that you shouldn't use this construct at all, so when should you vs when shouldn't you:

"Literal translations from English to Spanish don't work. In this context, do not use this type of construction in the English way:

"Estoy mirando a..." (I am looking forward to...)

"No puedo esperar a..." (I can't wait to...)"

Answer

Hola James
You're right. We don't normally use this when what we mean is "I can't wait to..." as explained in the lesson. We will be modifying the text and will turn that sentence into: "tengo muchas ganas de ver esas pinturas rupestres". 
As for the use of "a" with esperar, if we are saying "to wait to do something" (literally) we need the preposition "a", for example:

No puedo esperar a que te decidas. No tengo tanto tiempo.
I can't wait for you to decide. I haven't got that much time.

I hope this clarified it.
Saludos
Inma