Short medium what am I riddles

I am a giant sandbox built by nature. I have a coat of gold and a hem of blue, and I am the favorite place for a holiday view. What am I?

I am the place where the earth meets the sky and the water kisses the land. I disappear twice a day, only to return again. What am I?

I have a headboard but no brain, and a footboard but no toes. You visit me to travel to worlds that don't exist. What am I?

I have billions of tiny stones but no mountains. I have waves but no hair. People lie on me to feel the warmth of the sun. What am I?

What gets wet while it's drying?

As small as your thumb, I am light in the air. You may hear me before you see me, but trust that I'm there. What am I?

I am a vehicle. I spell the same when you read me forwards as well as backwards. What Am I?

I have more than 80 keys, but I cannot open any lock. What Am I?

I get whiter the dirtier I get. What am I?

I am something to make you think, I am something to make you know. I am something to which the answer you might never know. What am I?