Third one, about a couple of feet tall, could be a variety of Geranium phaeum.

..... called Mourning Widow?

From the leaves, the top one appears to be Geranium sanguinam of some variety - I can't tell if the flowers are pure white or whether they're marked or lined inside, but it might 'album' if they're pure white. If they're more pale pink with pink veining inside, G. sanguinam var. striatum.
Not sure about the pink one - its hard to tell what height the plants are from the pics.

I think the leaves on the first one look more like G. Clarkei to me. If they have magenta veins it could be 'Kashmir White'? They do look a lot like the ones I have in my garden as well.

Thanks everyone for your input! As they are not on my balcony it's not particularly important - I was just curious. I thought I might get a few cuttings & try & root them & then see if I can get them to grow on my balcony. I've often see them but I've never grown any of these Cranesbills myself.

I suppose they won't come true from seed, will they? Perhaps I could get photos of individual flowers when I next visit the garden.

First one - Kashmir White. Second, lovely with the darker leaves, but pink ones are hard to ID - sorry, I can't be more helpful on that one. Third one, G. phaeum definitely.

Most do come true from seed, by the way, - if they set them! The phaeums can be split, and you could well get seeds from the pink one.

Thanks very much, Spritz, I was surprised to hear they come true from seed!

You're welcome. If it's possible, could you please post a close- up of the pink flower as it might give me a clue. I have a useful book with photos of pink Geranium flowers. Oh, and measure the size, too!

Will post a new question with a few more photos on these Geraniums or I'll lose the uploaded ones. Will put the URL here once done. Here it is:

http://www.growsonyou.com/question/show/88806

Thanks in advance! :-))