Aesculus hippocastanum Hestekastanje Hästkastanj Hestekastanie Horse Chestnut
Familiar to all English kids as the conker tree, which if eated can give severe stomach ache.
The two lower images are Aesculus hippocastanum x carnea.
A manipulated version of the conker tree, with pink flowers.
If you look closely, you will see that the "white" horse chestnut flower also has pink (and yellow) petals.