To the north is a series of hills and more ravines.

The school resides on a rolling campus set into a series of hills.

They came to a crossroads and turned south, riding through a series of rolling hills.

Otherwise the road ran over a series of open hills.

For two hours they walked up and down a series of hills like those of the previous day.

Finally she came to a series of small hills shaped like little mountains.

To the west were a series of hills and mountains.

Even the sea was a series of hills and valleys no less real for constantly changing.

There the land rises in a series of high hills, some more than 1,000 feet above the lake.

A series of hills rise above the basin to the south.