Also, many negotiated rates have a drop dead date that requires your advance reservation to obtain the lowest rate.

FORBES: Why I Hate Travel Agencies

Starting 12 September, 2011, the National September 11 Memorial will be open to the public, day and night, by timed, advance reservation only.

BBC: 11 September history tour of New York

Far from being inaccessible, though, travellers just need to know where to look -- and have the foresight to call in advance for a reservation.

BBC: Hong Kong��s secret nightlife spots

Plan to eat early as the kitchen closes at 3:30 pm, although a special Tuesday evening reservation can be booked in advance for 50 euros, which includes a tour, a three-course meal and transportation to and from local hotels.

BBC: Dinner cooked by an active volcano