The valley of glass doors.

Question: What is in the valley of the glass doors. Listen to the words the houses have no roofs or doors, it just has walls. So what's in the valley of the glass doors?

Question: People see through me, but none pass through without killing me. I can be anywhere, and can be seen double or single. What am I?

Question: During what month do people sleep the least?

Question: When is 99 more than 100?

Question: What can be broken but never forgotten?

Question: What gets broken without being held?