Perhaps part of why I liked Portugal so much is that only a small percentage of the "must sees" have to do with churches. Don't get me wrong, I liked Belgium too, but I never need to see another baroque church as long as I live. I got my share in one little country.
First the Carmo Convent - Its a church that was destroyed in the great earthquake of 1755 leaving only its shell remaining. Inside the little gift shop area was two mummified children of about 8 years of age who were each squeezed into a 1x2 foot glass box for the world to walk by every day. It was really morbidly fascinating and as far as I could see had little relevance to the convent itself. I wasn't allowed to take pictures of them, so you'll have to trust me.
One day I spent almost 5 hours just sitting on the edge of Portugal near Cascais reading The Brooklyn Follies and wandering further up the coast every hour or so, or whenever it started raining onto my book. Along the way I came across El Boca Do Inferno!
And lastly the Jeronimos Monastery in Belem, the most peaceful place I may ever have been in my life. The cloisters were so lovely, too lovely to put into words.
And here is inside the actual church part. There was no flash allowed so I couldn't take a clear picture of a statue of a little saint who was stepping on the heads of 6 children. I'm getting the feeling that the Portuguese have an odd relationship with childhood.