Silbury Hill is a similar age, and a similar size to the pyramids.
Avebury Stone circle is also huge.
And the white horse at Uffington is both beautiful and awe inspiring.
Ancient people were capable of amazing things and had both vision and skill. We do them a disservice by assuming they were unable to undertake great works.
I highly recommend a visit to Avebury and Silbury Hill (only a few miles away) if you've never been there. Uffington's not far from there, and there is a big ring fort there, too.
As a filthy Welsh savage, all these places feel like part of my heritage.