1. Casco Viejo, also known as the Old Town of Bilbao, is the historic heart of the city located in the northeastern part of Bilbao, Spain. It is a charming and picturesque neighborhood with narrow streets, historic buildings, and a vibrant atmosphere.

One of the interesting facts about Casco Viejo is that it has been inhabited since the 14th century, making it one of the oldest parts of Bilbao. The area has undergone significant renovation and revitalization in recent years, making it a popular tourist destination. It is known for its mix of architectural styles, including Gothic, Renaissance, and Baroque.

Casco Viejo is home to several noteworthy attractions, including the Santiago Cathedral, which dates back to the 14th century and features a beautiful Gothic cloister. The Plaza Nueva, a lively square surrounded by arcaded buildings, is another highlight of the area. It is a popular meeting place and hosts a weekly market on Sundays.

In addition to its historical and architectural significance, Casco Viejo is also known for its gastronomy. The area is filled with traditional pintxo bars, where visitors can savor a variety of delicious Basque tapas, as well as specialty shops selling local products such as cheeses, chocolates, and wines.

2. The working hours of shops and establishments in Casco Viejo may vary, but generally, they are open from Monday to Saturday, from around 9:30 am to 1:30 pm, and then from 4:30 pm to 8:00 pm. On Sundays and public holidays, many shops and businesses are closed.

For specific information or inquiries, it is recommended to contact the Bilbao Tourism Office at +34 944 795 760 or visit their website.

3. Casco Viejo is easily accessible by public transportation. The nearest metro station is \"Casco Viejo,\" which is served by lines 1 and 2. There are also several bus lines that stop in the vicinity of the Old Town.

As for ticket information, there are no specific entrance tickets for Casco Viejo as it is a public area. However, some individual attractions within the Old Town may require separate admission fees, such as museums or guided tours. It is advisable to check with each specific attraction or inquire at the Bilbao Tourism Office for detailed information on tickets and transportation options.