ID Polish Tree with big pods

Friends recently gave me a couple of seed pods they'd picked up under a tree in Krakow. The tree was about 30 feet tall and the ground beneath was littered with these seed pods. Pods, if straightened will be 8 or 9 inches long and are about 1 and a half inch across. They contain small brown seeds about the size of sweet pea seeds but slightly flatter.
Can anyone help me with identification please?

 

Could be , Indian Bean tree seeds

Spruce

 

I think Spruce is right, far as I know Catalpa (Indian Bean) is the only tree with pods that large that could survive the Polish climate.

 

Dont look like Catalpa to me.
Catalpa seed is in a pod but winged, being from the Bignonia family.

This is a legume, I'm thinking Robinia or Gleditsia

Bearing in mind it gets very cold in Poland some winters.

 

Many thanks everyone, I knew I could rely on the GC crew to come up with an answer.
I've followed up all your suggestions by Googling and have arrived at the fairly firm conclusion that the parent tree was a Gleditsia as suggested by Pete.
The pods are too long for Robina and too broad for Catalpa.
I'll have a shot at sowing some of the seeds and see what transpires.

Thanks again, your replies put me on track and saved me hours!

 

Pete's right again

 

I picked some of these up today. After a bit of research, I've soaked mine in hot water. I'll sow them and let you know how I get on.

 

I think it is a Ceratonia siliqua, the Carob tree of which there are many here ...

http://en.wikipedia.org/wiki/Ceratonia_siliqua

It is very popular and they make lovely cakes from them ... it is a chocolate substitute.

 

All can say is that the pods I picked up today look identical to the ones in the photo. The tree mine came from had light green, feathery, cut leaves, giving light shade. Not like the ones on the Ceratonia siliqua.
I have a Catalpa tree, the pods are not the same as the ones produced by it.

 

I think the seeds that I have are from a Black/ Honey Locust bean tree.
I'll be in the area where I found them again next week. I'll try and get a photo of the tree.

 

Pretty certain the pods I was given are Honey locust / Gleditsia. The pods are like the top right photo that Marley has posted - a leathery brown colour and with about a dozen seeds in each pod. But I don't think that carob would survive in a Polish winter.
Anyway I sowed 5 seeds today and maybe in five years time I'll be able to post a photo of what the leaves look like.:WINK1:

 

Dave, it should be possible to get some idea this summer.