leenewham wrote:What is the international guest house?
This probably answers your question best:
![Image](http://farm3.static.flickr.com/2390/1853676545_043c28f236.jpg)
This is from an advertising leaflet, probably of the 1930s. The house was built in the 1850s or '60s. It became the International Hostel in 1927. During WW2 the hostel closed, and the house was demolished after the war. Modern housing now covers the site.
Where was it (is it still around?).
It was on the corner of Rock Hills, on the Dulwich side of Sydenham Hill, midway between the Dulwich Wood House and Westwood Hill roundabout.
Was it replaced by a 'better building'?
"Better building" is a matter of opinion, although I know the houses are well-regarded in some quarters.
Was this the most expensive postcard?
I would think not; because of its commercial use postcards of this building crop up fairly regularly. There are some more pictures of the house
[here]