How to explore ruins?

[Wrath of Westchester]

I simply don't get it. I have a Tactical Space Marine unit on top of the unexplored ruin but I don't see any button to explore it and ending the turn doesn't explore it.

What am I missing?

[Cursed Hawkins]

Is said ruins glowing yellow similar to a Necron Tomb?

[Wrath of Westchester]

Imperial Ruins
Sororitas Holy Site

Is that just one I cannot explore? It's not glowing.

[TemplarGR]

You cannot explore the holy sites without using the Adeptas Sororitas (Sisters of Battle) DLC faction. It is a mechanic tied to that faction. Those tiles with the "sparkles" can be explored by Sisters units and give some research points. Other factions can't gain research, they can only remove the Holy Site from the tile like clearing a forest or ruins, in order to remove it from the game and prevent the enemy Sisters of Battle from gaining research from it.