Looking on the internet deeply has found these results:

Going on vacations is the most popular phrase on the web.

going to vacations 1195,000 results on the web	Going on vacations 1401,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
I thought you were going on vacation to find yourself. He's going to spend his vacation in Loreto. What are you going to do on vacation? Why are you going to Aspen, vacation? You're going to be alone as the new president for a while because Ann and I are going to take a vacation. He said he was going to get the vacation fund back. He's going to Biarritz on vacation. You and me and Lisa are going on vacation to China together.	But, Barney, we're not going on vacation. No, I'm going on vacation. Is your family going on vacation? I thought you were going on vacation to find yourself. I'm never going on vacation again. We weren't going on vacation, though. They're going on vacation during Thanksgiving. It looks like you're going on vacation in the Bahamas.

going to vacations

1195,000 results on the web

Going on vacations

1401,000 results on the web

More popular!

I thought you were going on vacation to find yourself.
He's going to spend his vacation in Loreto.
What are you going to do on vacation?
Why are you going to Aspen, vacation?
You're going to be alone as the new president for a while because Ann and I are going to take a vacation.
He said he was going to get the vacation fund back.
He's going to Biarritz on vacation.
You and me and Lisa are going on vacation to China together.