Denver-based Frontier Airlines on Tuesday announced the addition of 20 new nonstop routes, including several international, in what company officials are calling “one of our largest international expansions ever.”

The introductory fares are sure to raise some eyebrows: As of Dec. 11, travelers can fly from Denver International Airport to Belize for $99.

While DIA only got one new weekly route, to Belize, the airport connects to Frontier’s Orlando, Florida, hub, where new routes can be taken to Antiqua and Barbuda; Liberia, Costa Rica; and Turks and Caicos.

“Today’s announcement marks one of our largest international expansions ever and we are thrilled to now offer our customers affordable service to four more popular destinations offering both sun and fun,” Daniel Shurz, senior vice president of commercial, said in a statement.

“Summer 2021 has led to phenomenal growth for Frontier and this announcement of 20 new routes comes on the heels of 21 that we unveiled just last week. Frontier travelers now have more route options than ever before to explore, while at the same time knowing they’re flying on America’s Greenest Airline, with a young fleet that maximizes efficiency every flight.”

Promotional fares must be purchased by Aug. 2.

In April, the company added new flights out of DIA to Grand Junction and Durango; Anchorage, Alaska; and Kalispell, Montana. Those routes started in June.

The new route means Frontier offers flights to and from 85 destinations via DIA this summer.

Frontier has more than 1,900 employees based in Colorado. It also has a maintenance facility and training facility in Denver.