Which province was the capital of the first three feudal dynasties in Vietnam?

A simple puzzle for history buffs who are passionate about learning about origins.

The question sounds simple, but to answer it correctly you must really know history.

What province is this?

Leave your answer in the comments section and see if there are any matching answers.

Giang Pham

Source: https://vtcnews.vn/tinh-nao-tung-la-kinh-do-cua-3-trieu-dai-phong-kien-dau-tien-o-viet-nam-ar972733.html