It is not lawful for a woman believing in Allah and the Hereafter to undertake journey extending over a day and a night except when there is a Mahram with her.
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ يَحِلُّ لاِمْرَأَةٍ تُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الآخِرِ تُسَافِرُ مَسِيرَةَ يَوْمٍ وَلَيْلَةٍ إِلاَّ مَعَ ذِي مَحْرَمٍ عَلَيْهَا