In terms of SEO, this:
is better, and even well accepted by Google because as part of Google's Webmaster Guidelines, they appreciate a hierarchal type of URL layout which is what this URL has. Additionally, management of each section of the site is far easier to the point where you can assign a customer (hotel owner I assume) a folder just for the hotel.
For example, if you have one owner that can manage SeaView Hotel, and another owner that can manage Cat Hotel, and both are located in Egypt, then your folder structure on your website can be as follows:
In document root, make a folder called "egypt". then in the "egypt" folder, create two folders. One named "seaview hotel" and one named "cat hotel". Next assign FTP access to each hotel folder with different usernames and passwords so each customer can manage his/her hotel online.
As for creating a true mirror Google will accept, copy all website files from the customers website (including the index file) to the applicable hotel folders then modify any configuration files like .htaccess file to make the hotel site fully functional. Then on either domain make use of the
rel=canonical tag and have it point to the preferred domain.
For example, if the customers domain is http://example.com and you want a mirror at http://www.example.com/egypt/cat-hotel then in the cat-hotel folder, add to every file that produces HTML output the following:
<link rel="canonical" href="http://example.com">
That way, you'll get the same content at both locations while making Google understand its the same content without it flagging you down and issuing a "duplicate content" penalty. It will only index pages from one of the two sites.
See this for more info: