Dubai and Doha
Wandering Dubai and Doha. Wandering two cities that didn't exist fifty years ago, and only sprang up in their modern form in the past 20 or 25 years. Add in the fact that both countries (United Arab Emirates and Qatar) are both actively trying to modernize and strengthen their economies in preparation for when their petroleum reserves run out, and the experience is truly unique: two countries with the resources and the drive to improve their economies from the highest level.
A very, very different experience from much of the world, from the already-established Western countries to the hopelessly-corrupt African (and other) nations.
Days 1 and 2 - up early, off to IAD, evening flight from IAD-DXB means an afternoon arrival in Dubai the next day. Gawk at the tall buildings and hustle off to Dubai Marina to explore.
Day 3 - old town Dubai, Dubai Creek, Dubai Mall, and the Burj Khalifa.
Day 4 - Jumeriah Mosque in Dubai, then off to Doha.
Day 5 - Souq Walif, Museum of Islamic Art, City Center and West Bay, plus lots of roasting in the heat.
Day 6 - The Gate Mall, then back to Dubai.
Day 7 - DXB to IAD and return.