It is not lawful for a Muslim woman to travel the distance of one night unless accompanied by a man who is a Mahram (non-marriageable male relative) to her

Ibn Hajar said: The impermissibility of a woman traveling without a Mahram, and this is a consensus except in the cases of Hajj and ‘Umrah, and leaving the land of Shirk (polytheism). However, some scholars have made this a condition for performing Hajj.
The perfection of the Islamic Shariah and its deep concern for safeguarding and protecting women.
Belief in Allah and the Last Day requires submission to the legislation of Allah and abidance by His limits.
A woman's Mahram is her husband or someone who is permanently prohibited from marrying her due to blood relations, breastfeeding, or marriage ties. He must be a Muslim, adult, sane, trustworthy, and reliable, as the purpose of a Mahram is to protect and safeguard the woman and take care of her needs.
Al-Bayhaqi said regarding the narrations related to the duration of travel for which a woman is not allowed to travel except with a Mahram: In conclusion, anything that is called travel, a woman is prohibited from undertaking it without a husband or a Mahram, whether it is for three days, two days, one day, a Barīd (a specific distance measurement), or anything else, due to the general indication of the narration of Ibn ‘Abbās, which is the last of Muslim's previous narrations: "A woman must not travel except with a Mahram." This applies to all that is called travel. End quote. This Hadīth was based on the condition of the questioner and his country.