The currency in Peru is the Nuevo Sol. US Dollars are also often accepted in tourist areas.
ATMs can be found in all towns and cities in Peru. Most major credit cards are accepted, although it's not usually possible to use credit and debit cards for purchases outside of tourist areas so a combination of cash and cards is always best.
Important: Please be aware that ATMs in Peru do not always automatically release your card with your cash and sometimes you have to push a button for your card to be returned.
Although all major currencies can be exchanged locally, US Dollars are best. It's advisable to request bank notes in smaller denominations, as it can sometime be hard to get change from larger notes.
Traveller's Cheques are not recommended as they're often difficult to exchange and incur high fees.