Yes, you can take cash out from cash machines anywhere in the world displaying the MasterCard, Cirrus sign (for MasterCards) or VISA sign for Visa cards. You can also withdraw cash over the counter in banks.
Please remember though that this is seen as a cash advance on a credit card and there is a fee to do this.
The fee is 3% of the amount of cash that you withdraw (with a minimum of a £3 fee). It is also important to note that interest for taking cash out on a credit card is incurred from the day you withdraw it, rather than after the next payment date as per other types of transactions.